Renewable fuse



G. A. BURNHAM.

RENEWABLE FUSE.

APPLICATION FILED OCT. 4, I918.

Patented Jan. 24, 1922.

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UNITED STATES PATENT OFFICE.

GEORGE a ZBURNHAM, or sauces, massacnnsnrrs, assronoa 'ro smsas B. comm,

3a., or maooxnmn, massacnusn'rrs,

amwunn roar.

Specification a: Letters Patent.

Patented Jan. 24, 1922.

application filed October '4, 1918. Serial No. 256,797.

I '0 dz; whom it may concern Be it known that I, Gnoaon A.- BURNHAM,

a citizen of-the United States, residing at Saugus, in the county of Essex and State of has more particular reference to fuses of the refillable type in which the fusible element thereof is replaceable upon necessity by a new fusible element.

In refillable fuses it is universal practice to inolose the fusible elements thereof in a tube or cylinder of non-conducting material such as fibre and to provide various means for sealing or completely enclosing the fuse therein .which, however, will permit the opening of said tube for the renewal of a burned fusible element.

Many types of refillable or renewable fuses are on the market all of which are more or less complicated and very expensive to manufacture. All of these refillable fuses are designed to fit the standard type of fuse (fzlip adapted to receive an inclosed tubular use.

The object of m invention is in the provision of a renewable fuse which has all the advantages of the inclosed refillable fuse and which is ada ted to be received in the standard tubular use clips.

Briefly, I accomplish the object of my inventionby providing a tube having open ends through which the fusible element is adapted to be extended and thereby rotected by the walls of the tube, the tube thereby forming a tubular barrier entirely surrounding the fusible element. Ferrules or end caps are arranged on the tube, at the extremities thereof and may have ears or the equivalent thereon, between which the fusible link or element is adapted to be detachably connected, whereby upon the fusing of a link, a second link may be secured thereto to again condition the fuse for operation.

By reason of the tubular barrier surrounding the fusible element, all of the advantages of the enclosed type of fuse are retained and, by reason of the open ends of the tube the desirable expulsion action occurs upon the blowing of the fuse, thereby aiding in the extinguishment of the arc.

Furthermore, by this construction, a very simple and inexpensive type of renewable fuse is obtained and in which the renewable fusible element is easil replaced.

Certain features of this invention are shown but not claimed in my co-pending appglcttion Serial No. 247,97 6, filed August 2,

Fig. 1- is a side elevation of a renewable fuse embodying my invention as associated with a fuse block shown partly in section.

Fig. 2 is a sectional elevation of the fuse of- Fig. 1.

f- Fig. 3 is perspective view of an end of the use.

As here shown, the renewable fuse includes the tubularcasinQ-"IO of an insulating material such as fibre having a relatively large internal diameter which may vary accordin to the capacity of the fuse and a length which also may vary according to the capacity of the fuse. Said tube is open at each end. Cylindrical end caps or ferrules 11 are arranged on said tube at the extremities thereof and are of a diameter and width corresponding to the end caps or ferrules of the standard type of inclosed fuse whereby the fuse may be received in the standard tubular fuse clips shown at 12 as arranged on a standard typle of fuse block 13.

ach of said end caps or ferrules 11 may be provided with a refiexed portion or ear 14 which is upturned and extended towards each other above the body of the fuse. Each car 14 is provided with attaching means, as screws 15, by means of which the extremities of a fuse link 16 may be secured thereto.

Said fuse link 16 may comprise a strip of fuse wire or other fusible element of relatively small cross-section extended through said tube 10 and the ends thereof brought up and secured to the cars 14 of the endv tively great distance from the side-wall of a the casing.

A refillable fuse constructed as above described performs all the functions of the renewable inclosed fuse at present constructed.

' The tube 10 forms a tubular barrier surroundin the fusible element thereby inclosing t e fuse and preventing the are resulting from the fusing of one element from effecting an adjacent fusible elementJ'Furthermoie this type of fuse has advanta es peculiar to itself. By the provision of t e open ends of the tube 10, an expinlsive operav in connectin 'the fuse blows or fuses, the hot forcibly driven from theends of the tubes thereby quickly to quench the arc. he reflexed ears form t on of the fuse is obtained w ereby', when gases are 'By the provision of means between the .end ferru es for'the' use, the 'connect-mg means do not extend beyond the extremities j of' the tubular portion, and the'fuse may thereby be used in any fuse blockada ted toreceive a standardtubular inclosed se, such, for instance, as shown in Fig. 1, having the barrier wise, made, this connection might rotrude fromthe end'of the fuse and interf gre with t Q the roper arrangement of the fuse within I the'useclipfif- 3 to v I claim: A refillable sulat'ing casing having a relatlvely large internal diameter and open ends, end ferrules carried on the outside of'said casing at the 1 ends thereof'having oppositely disposed upwardly extended ears with fuse-element at! taching means thereon, and a fusible element having a' relatively small cross-section 'as compared with the internal diameter ofsaid casing disposed within said casin and spaced from the side-wall thereof hav1n its ends extended through theopen ends '0 the fuse comprising a tubular in- 30' casing and upwardly and secured to the ears .of said'end ferrules.

In testimony whereof, I have signed my name to. thisspecification, in the presence of two subscribing witnesses.

Witnesses: T. T. GREENWOOD,

H. B.- DAvIs.

' GEORGE BURNHAM. g 

